APPLICANT'S ABSTRACT: This application requests renewal of a Research Scientist Award to enable the candidate to pursue full time research and research training aimed at improving diagnostic and psychosocial treatment strategies for drug abusers. During the renewal period the applicant will conduct research projects of two types: a. clinical trials to assess the efficacy of promising psychosocial interventions, b. projects to improve the methods of classifying substance abusers with the particular aim of defining clinically meaningful subgroups. The Research Plan provides a detailed description of our trial of CRA and naltrexone for opioid dependence. The disappointing record of naltrexone, an excellent, long acting opioid antagonist, in the substance abuse treatment system, may in part be due to failure to combine it with psychosocial approaches to enhance compliance with naltrexone and reward abstinence. The multifaceted CRA approach developed by Higgins and colleagues is particularly attractive as a strategy to improve outcomes in naltrexone treatment because several of its components could be targeted to directly address naltrexone's weaknesses. For example, to compensate for naltrexone's lack of pharmacological reward, contingency management through use of a voucher system could be used to reward and enhance naltrexone ingestion. 180 recently detoxified opioid addicts will be randomly assigned to either (1) contingency management plus significant other involvement in addition to standard naltrexone treatment, (2) contingency management in addition to standard naltrexone treatment, or (3) standard naltrexone treatment alone, consisting of thrice weekly clinic visits for naltrexone, thrice weekly supervised urine toxicology screens, and weekly group counseling. Primary outcomes will be retention, compliance with naltrexone treatment, and reduction in opioid, cocaine, and other substance use.